Biology subjects

Pudasaini, R.

Publications and source records attributed to Pudasaini, R..

3 recordsLinked to original sources

bioRxiv2026

Coordinated neural, metabolic and muscular transcriptomic signatures associated with mite-biting behavior in honeybees (Apis mellifera L.)

Biting behavior is an important natural defense mechanism in honeybees (Apis mellifera) against Varroa destructor. Significant variation in this behavior exists across genetic lines of honeybees, with certain colonies exhibiting higher mite-biting activity than others. Selective breeding for enhanced biting behavior provides a promising strategy for sustainable mite control and colony resilience. However, successful implementation of such breeding programs requires a comprehensive understanding of the genomic mechanism underlying this trait. In this study, RNA-seq analysis of mandible transcriptomes of 1-day and 8-day old worker honeybees from high mite biting (HB) and low mite biting (LB) colonies were performed. A total of 9,345 genes (97.30%) showed a significant differential expression between LB and HB honeybees across different ages (one-way ANOVA, FDR < 0.05). Comparison of LB vs. HB workers collected on day 1 detected 166 down-regulated and 403 up-regulated genes, whereas workers collected on day 8 identified 82 down-regulated and 46 up-regulated genes. Furthermore, the Weighted Gene Coexpression Network Analysis (WGCNA) exhibited the brown and yellow modules with significantly higher expression in HB compared with LB on both day 1 (FC = 1.52, FDR = 0.0019 and FC = 1.47, FDR = 2.7 x 10-4, respectively) and day 8 (FC = 1.27, FDR = 0.056 and FC = 1.16, FDR = 0.073, respectively). Gene Ontology (GO) enrichment analysis identified over-representation of biological processes involved in muscle contraction, chitin binding, neural signaling, oxidative phosphorylation, neuron development, electron transport chain, mitochondrial ATP synthesis, stress response, sensory perception and metabolic processes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis identified significant enrichment of various pathways including oxidative phosphorylation, cytoskeleton-related pathways, carbon metabolism, motor proteins, ribosome-associated pathways, and citrate cycle (TCA cycle). The present findings demonstrate mite-biting behavior is associated with coordinated activation of neural, energetic and muscular system rather than a single molecular mechanism. These findings provide a basis to improve honeybee health, enhance resistance to Varroa and other ectoparasite, and eventually support sustainable beekeeping and agricultural pollination systems.

genomics↗

bioRxiv2026

Spatiotemporal variation in honeybee (Apis mellifera L.) virome composition across landscape types and seasons

Honeybees face increasing threats from biotic stress of viral pathogens that can severely impact colony health and contribute to global colony decline. However, comprehensive studies of biotic stress and composition of bee viruses across different environmental contexts and seasons remain scarce. This study aims to characterize and compare the diversity, abundance and composition of the Apis mellifera L. virome across three different landscapes (conventional, organic, and roadside) and seasonal gradients (early vs. late season) to better understand how environmental and temporal factors affect viral communities in honeybees. A. mellifera were collected from three different habitats (conventional farm, organic farm, and roadside habitat) during the spring and summer of 2024. Total RNA was extracted individually from whole honeybees and mRNA libraries were prepared, which were subsequently used for sequencing on an Illumina NovaSeq X Plus platform using paired-end 150 bp reads. Several bacteriophages, putative novel viruses, plant-, insect- and bee-associated viruses were detected in the honeybee viromes including Sacbrood virus, Black queen cell virus, Deformed wing virus-B (previously known as Varroa destructor virus-1) and Deformed wing virus. Furthermore, both habitat types and seasons influence viral abundance as majority of detected viruses showed higher abundance in the conventional farm and late season samples. The present findings provide novel insights into the ecological and seasonal dynamics of honeybee-virus interactions and contribute to strategies for improving honeybee health and resilience.

ecology↗

bioRxiv2025

Developmental and Environmental Stability of Candidate Reference Genes in the Wild Bee Ceratina calcarata

Quantitative real-time PCR (RT-qPCR) is a widely used method for measuring gene expression, but its accuracy depends on the use of stable reference genes for data normalization. In this study, we evaluated the expression stability of seven candidate reference genes (RPS18, RPS5, RPL32, RPL8, EF-1, {beta}-Actin, and GAPDH) in the small carpenter bee Ceratina calcarata across developmental stages (larvae, pupae, adults) and different landscape environments (conventional farms, organic farms, and roadside sites). Using four analytical algorithms, GeNorm, NormFinder, BestKeeper, and the comparative {Delta}Ct method, we identified RPS18 and RPL8 as the most stable reference genes under varying biological and environmental conditions. These findings were further supported by RefFinder, which integrates results from all algorithms. Our study provides the first validated reference genes for C. calcarata, enabling more accurate and reproducible gene expression analysis in this ecologically important wild bee species. This work will support future research in pollinator biology, environmental stress responses, and conservation genomics.

genomics↗